Microwave radiation is known as a physical agent which can cause changes at
the level of DNA synthesis and its structure. The micronucleus assay is widely
used as a method for the evaluation of cytogenetic damage in both in vivo and
in vitro environmental mutagenesis. Therefore our aim was to investigate the
genotoxic effects of microwave radiation by micronucleus test in human
lymphocytes experimentally exposed to particular intensities of microwave
radiation.

Human whole-blood samples were exposed to continuous microwave radiation with
frequencies 2.45 GHz and 7.7 GHz. In both cases, the power density was 10, 20
and 30 mW/cm2 for 15, 30 and 60 min. of exposition. The results, analyzed by
using Fisher's exact test, showed for both frequencies of radiation an
induction of micronuclei in the exposed samples higher than in the control at
power density of 30 mW/cm2 and after 30 and 60 min. of exposition.

Our study
indicates that induced cytogenetic damage in human lymphocytes may be either
power density- and/or time exposition-related.